Setting map bounds for multiple markers

gistfile1.txt

 function setMarkers(map) {
        
        var bounds = new google.maps.LatLngBounds();            
          
        for (var i = 0; i < restaurants.length; i++) {
            var restaurant = restaurants[i];
            var layerposit = (restaurant[4] == 1 ? 999  : restaurant[3]);
            var marker = new google.maps.Marker({
                position: {
                    lat: restaurant[1], 
                    lng: restaurant[2]
                },
                map: map,           
                title: restaurant[0],
                zIndex: layerposit
            });
            bounds.extend(marker.getPosition());
        }
        map.fitBounds(bounds);
    }